To compare these decimals you need to compare their place values.

units

tenths

hundredths

thousandths

3

.

1

3

8

3

.

1

4

Since the 4 in the hundredths place of the second number is larger than the 3 in the hundredths place of the first number, the second number is larger than the first. The comparison of these two numbers is not affected at all by the 8 in the first number.

Now practice sorting fractions from least to greatest: